Bernhard (radio beacon)

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FuSAn 724 ready for action in occupied Denmark

The VHF - very high frequency omnidirectional conditioning Pusan 724/725 , code name "Bernhard" was developed by Telefunken and served during World War II aircraft to determine its own position.

The large transmitting antenna rotated twice per minute on a ring of rails more than 22 meters in diameter and transmitted a signal that was modulated according to its rotational position . On board the aircraft was next to the Hellschreiber (FuG 120 Bernhardine ) with driver amplifier and a switching device does not require any additional equipment because the required FM receiver EBl 3 for 30 to 33.33 MHz already part of FuBl two-board system of Lorenz - landing system was . The Hellschreiber recorded the received signals on a strip of paper.

The most important part of the "Bernhard" were two antennas connected to each other on the narrow side , but they did not form a continuous surface, but were arranged at a slight angle to each other. With this design, the two antennas created two overlapping directional lobes . The sharp minimum in between showed the exact main beam direction of the system. With the reception of the beam directions of two "Bernhard" rotary radio beacons, the on-board navigator was able to determine its own current position on the map.

Systems were located in Trebbin ( OT Glau , location , northeastern peace town Weißenberg ), Den Helder , Bergen-Belveder, Hundborg / Denmark ( location , today Thisted municipality ), on the Venusberg near Aidlingen (Baden-Württemberg) and at around 20 other locations.

Technical specifications

Plant under construction. The feed lines between the dipole groups are still missing
Back, construction status at the end of 1941
  • Frequency : 30 to 33.1 MHz
  • Transmission power : 2 × 500 W (FuSAn 724) or 2 × 5000 W (FuSAn 725)
  • Range : 400 km at an altitude of 5000 m
  • Accuracy +/- 0.5 °
  • Year of construction: from 1941
  • Height: 28 m
  • Width 35 m
  • Mass: 120 t
  • Track ring diameter: 22.6 m

literature

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